1. Executing
The Energy Supply Plan
Financial
Performance
Regulators/
Legislators
Value to Environmental
Customers Stewardship
Invest in Regulated Utility Business
David Wilks President – Energy Supply

2. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills

3. Coal Plant Non-Fuel O&M Expense
Dollars per MWh 2004 average
14
12
10
8
6
3.65
4
2
0
Xcel Energy
US Electric Holding Companies
Source: Credit Suisse First Boston November 1, 2005 Report –
Costs of Doing Business

4. Coal Plant Fuel Expense
Dollars per MWh 2004 average
30
25
20
15
11.33
10
5
0
Xcel Energy
US Electric Holding Companies
Source: Credit Suisse First Boston November 1, 2005 Report –
Costs of Doing Business

5. Nuclear Fuel Expense
Dollars per MWh 2004 average
8
6
4.64
4
2
0
Xcel Energy
US Electric Holding Companies
Source: Credit Suisse First Boston November 1, 2005 Report –
Costs of Doing Business

6. Xcel Energy Supply Sources
2004 2005 Owned
Energy Supply Mix* Generating Facilities
Unit Type Number MW
Nuclear
Gas Coal 36 8,138
12%
27% Natural Gas 61 4,918
Renewables
Nuclear 3 1,617
7%
Hydro 83 508
Oil 24 492
RDF 6 96
25 *
Wind -
Coal ** Total 15,794
54%
* Additionally, Xcel Energy
* Includes purchases purchases 928 MWs of wind
** Low-sulfur western coal power

7. NSP Supply Sources
2004 2005 Owned
Energy Supply Mix* Generating Facilities
MW
Unit Type
Renewables
3%
Nuclear Manitoba Hydro Coal 3,375
28% 11% Natural Gas 1,758
Total Other Nuclear 1,617
Purchases Purchases
Hydro 266
Gas 12%
Oil 492
2%
RDF 96
Total 7,604
Coal**
44%
* Includes purchases
** Low-sulfur western coal

8. PSCo Supply Sources
2004 2005 Owned
Energy Supply Mix* Generating Facilities
Purchases Unit Type MW
37%
Coal 2,617
Gas
Natural Gas 982
11%
Renewables
Hydro 242
0.2%
Wind 25
Total 3,866
Coal **
52%
* Includes purchases
** Low-sulfur western coal

9. SPS Supply Sources
2004 2005 Owned
Energy Supply Mix* Generating Facilities
Unit Type MW
Purchases
Gas Coal 2,146
20%
24% Natural Gas 2,178
Total 4,324
Coal **
56%
* Includes purchases
** Low-sulfur western coal

10. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills

11. NSP Major Fossil Plant Availability
Percent
89
88 87 85
83 83
2001 2002 2003 2004 2005 2005 YTD
YTD without
3rd Qtr MERP units

12. NSP Nuclear Plant Availability
Percent
95 94 93
85
83
2001 2002 2003 2004 2005
YTD 3rd Qtr

13. PSCo Major Fossil Plant Availability
Percent
90 90 89
88
87
2001 2002 2003 2004 2005
YTD 3rd Qtr

14. SPS Major Fossil Plant Availability
Percent
91 91 90 89 86
2001 2002 2003 2004 2005
YTD 3rd Qtr

15. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills

16. CAIR and Mercury Compliance Plan
Colorado is exempt from CAIR
Filed suit contesting inclusion of West Texas
in CAIR
NSP SO2 credits to last through 2020
SPS to purchase SO2 allowances
Investment of $50 – 60 million to meet NOX
standards at NSP and SPS
PSCo expected to meet mercury reduction
requirements with Comanche 3 and
Comanche 1 & 2 modifications
Testing and evaluating approaches to reduce
mercury at NSP and SPS

17. Environmental Compliance
Costs Minimized by Allowance
Purchases and Investment
Dollars in millions
350
300
Allowances Capital
250
Investment
200
150
100
50
0
Allowances 100% 0%
Investment 0% 100%
Note: The curves are conceptual

18. NSP Environmental Initiatives
Owned generation (GWh) Pounds per MWh
40,000 5.0
35,000
4.0
30,000
25,000 3.0
20,000
2.0
15,000
10,000
1.0
5,000
0.0
0
1997 1999 2001 2003 2005 2007 2009
Forecast
Nitrogen Oxides emissions
Owned generation (GWh)
Sulfur Dioxide emissions

19. PSCo Environmental Initiatives
Owned generation (GWh) Pounds per MWh
35,000 8.0
30,000
6.0
25,000
20,000
4.0
15,000
10,000 2.0
5,000
0.0
0
1997 1999 2001 2003 2005 2007 2009
Forecast
Nitrogen Oxides emissions
Owned generation (GWh)
Sulfur Dioxide emissions

20. SPS Environmental Initiatives
Owned generation (GWh) Pounds per MWh
35,000 8.0
30,000
6.0
25,000
20,000
4.0
15,000
10,000 2.0
5,000
0.0
0
1997 1908 1999 2000 2001 2002 2003 2004 2005
Forecast
Nitrogen Oxides emissions
Owned generation (GWh)
Sulfur Dioxide emissions

21. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills

22. Energy Supply Sourcing Initiatives
YTD Delivered Sourcing Savings Sourcing Savings
Maintenance Repair
Dollars in thousands
942 and Operations (MRO)
830 O&M Capital
Turbine Overhaul Initiative
526
Characteristics
192
Provide cost savings
32 4
Consolidate supply base
Price Cost Value
Savings Avoidance Added
Includes supplier
Sourcing Savings (millions)
performance program for
O&M Total = $1.0
continuous improvement
Capital = $1.5
YTD Total = $2.5
YE Projections/Negotiated ~ $7.0

23. Energy Supply Plant
Condition Assessment
Colorado (Overall)
Auxiliary
Boiler Water Makeup
Circ Water Makeup
CT Water Makeup
Ash
Fuel Handling
FGS
Environmental
Generator
Reservoir
Forebay
Diesel Engine
Combustion Turbine
Soot Blowing
Turbine
Water Gathering
Electrical
Fuel
Power Tunnel
Support Equipment
Plant
Boiler
Cooling Tower
Feedwater
Condenser
Steam
Controls
Emissions
Radiators
Circulating Water
Equipment
Units
N Y N N G N N N N G G N N N G N G G N N N N N N G
Alamosa 1
N G N N G N N N N G G N N N G N G G N N N N N N G
Alamosa 2
Y G G R Y G R N G Y G N N Y Y G N Y G N N N Y R G
Arapahoe 3
Y G G Y G R R N G G Y G N N Y Y Y N Y G N N N R Y
Arapahoe 4
N G N N N N N N G Y Y N N N N N G N N N N N Y N
Cabin Creek A
N G N N N N N N G Y Y N N N N N G N N N N N Y N
Cabin Creek B
Y G G R Y N R N G G G G N N N R Y R N G G N N N Y R
Cameo 1
Y G G Y Y N R N G G G Y N N N R R N R N G G N N N Y R
Cameo 2
Y Y Y Y G G G N Y G Y R N N R Y G N Y Y N N N G Y
Cherokee 1
Y Y Y Y R G G N Y G G R N R Y G N G G N N N G Y
Cherokee 2
Y Y Y Y G G G N Y G G R G R Y G N Y G N N N G G
Cherokee 3
Y Y Y G Y G G N Y G G R N G R Y Y N G G N N N G G
Cherokee 4
Y Y Y Y G G Y N Y G Y Y N N G Y N Y N G G N N N Y Y
Comanche 1
Y Y G Y Y G Y N Y G Y Y N G G Y G N R Y N N N Y Y
Comanche 2
N G G Y G N N G Y N N Y Y N N G N N N
Denver Steam
N G N N G N N N N G G N N N G N N G G N N N N N N G
Fort Lupton 1
N G N N G N N N N G G G N N N G N N G G N N N N N N G N
Fort Lupton 2
N Y G N Y Y Y N G Y Y Y N N N G Y N Y Y N N N N Y G G
Fort St Vrain 1
N G N G G N N N N N G Y N N N G G N G Y N G N N N N N N
Fort St Vrain 2
N G N G G N N N N N G G N N N G G N G G N N N N N N N N
Fort St Vrain 3
N G N G G N N N N N G G N N N G G N G Y N G N N N N N N
Fort St Vrain 4

24. Energy Supply Additional
Cost Saving Initiatives
Insurance Premiums YTD 2005
Cost Savings
Dollars in millions
18
Insurance premium $2.6 M
15
12 Vendor management
meetings 1.3
9
$6.9 Cost Reduction
6
MRO alliances 0.6
3
Total savings $4.5 M
0
2003* 2004* 2005* 2006*
* Year ended June

25. Energy Supply Material Inventory
Dollars in millions
82
78 74 73
2002 2003 2004 2005 YTD
3rd Qtr

26. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills

27. Completed Construction Projects
Fort St. Vrain
737 MWs
Completed May 2001;
on-time and within budget
Black Dog 5
162 MWs
Completed November 2002;
on-time and within budget

28. Prairie Island Steam Generators Replaced
Two units, 1076 MWs
which began commercial
operation late 1973/1974
Steam generators
replaced on unit 1
November 2004 after
30 years of operations
Project completed on
time and within budget

29. NSP New Gas Units
Blue Lake
2 combustion turbine peaking
units totaling 320 MWs installed
Online May 2005; on time and
under budget
Capacity factors of 16% and
18% from June through August
Angus Anson
One 160 MW combustion
turbine peaking unit installed
Online May 2005; on time and
under budget
Capacity factor of 25%
for June through August

30. NSP MERP — King Plant
Detailed design work is 65%
complete
Artist Rendering Piling work is complete;
One Unit – 571 MWs foundation installation work
continues
First permanent support
steel was set on August 3,
as scheduled
SCR and AQCS components
continue to be received at the
site. Initial SCR ductwork was
installed during September
outage
Scheduled for commercial
operations May 2007

31. NSP MERP — High Bridge Plant
Signed contract for
Artist Rendering purchase of 2 CTs and
575 MWs 1 steam turbine. Resulted
in $40 million savings
Gas pipeline awarded to
NSP Gas
All permits have been
issued and site remediation
work began August 2005
Full construction release
Project planned to be
completed by May 2008

32. NSP MERP — Riverside Plant
Artist Rendering Asbestos abatement,
520 MWs mercury and lead removal
activities underway on old
section
Began site development
study in April 2005
Permitting and equipment
design began in Fall 2005
In-service scheduled for
May 2009

33. PSCo Comanche 3
PUC approval January 2005
Artist Rendering Major contracts signed for
One Unit – 750 MWs Net turbine generator, boiler and
air quality control system –
within budget
Air permit approved
July 15, 2005
Began construction in
October 2005. Major
contractors start May 2006
Construction completed fall
2009 at a total cost of $1.35
billion
New unit $1.073 B
Transmission $150 M
Retrofit 1 & 2 $127 M

34. NSP Nuclear Relicensing Status
Monticello
Minnesota PUC, legislative and NRC approvals
expected 2006 – 2007
Life Cycle modifications to be installed 2008 – 2012,
projected capital cost of $150 – 200 million
Prairie Island
Begin license application to the NRC and
Minnesota Legislature in 2008
Life Cycle modifications under evaluation
Approvals expected 2010 – 2011

35. Energy Supply Capital
Expenditures 2001 – 2009
Dollars in millions
800
MN MERP
700
Comanche 3
600 Blue Lake CTs
500 Angus Anson CTs
400 TX CAIR/Hg
300 MN CAIR/Hg
200 Base Budget
Actual
100
0
2001 2002 2003 2004 2005 2006 2007 2008 2009
Forecast

36. Excellence in Generation
Strong operational performance
Environmental stewardship
Strong cost management
Proven construction management skills